title: Induction of cutaneous lymphocyte-associated antigen expression by group A streptococcal antigens in psoriasis.
abstract: The cutaneous lymphocyte-associated antigen (CLA) has been proposed as a homing receptor for the selective migration of memory T cells into the skin. To investigate the effect of group A streptococci (GAS) on the migration of T cells in psoriasis, CLA expression was assessed by double-staining for CD3 and the HECA-452 epitope on peripheral blood T cells from 13 patients with psoriasis, 10 patients with other inflammatory skin diseases and 12 normal controls before and after 7 days culture with a GAS sonicate, Candida albicans (control antigen) or medium. In addition, CLA+, and CLA-, CD3+ CD45RO+ subsets were isolated from individuals in each group and V beta 2 expression and proliferation to GAS studied. Mean CLA expression by freshly isolated T cells was almost identical in the three groups. After culture with GAS, T cells from the psoriatic patients and control showed a significant increase in mean percentage CLA+ expression compared to medium (P < 0.002, P < 0.05, respectively). This induction was inhibited by the addition of anti-IL-12 antibody. However, in psoriatic patients, but not in controls, the GAS-induced increase was significantly greater than that of C. albicans (P < 0.002) and was accompanied by a decrease in T cells positive for the peripheral lymph node homing receptor, L-selectin (P < 0.05). The percentage of V beta 2+ T cells was markedly higher in the CLA+ than in the CLA- T-cell subset in psoriatic patients (P < 0.01) and controls; both subsets proliferated to GAS, in each group. These findings suggest a differential modulation of specific tissue homing receptors on T cells by GAS in psoriasis.
authors.affiliation: Department of Dermatology, St. Mary's Hospital, Paddington, London, UK. b.baker@ic.ac.uk
authors.forename: B S
authors.initials: BS
authors.lastname: Baker
authors.forename: J J
authors.initials: JJ
authors.lastname: Garioch
authors.forename: C
authors.initials: C
authors.lastname: Hardman
authors.forename: A
authors.initials: A
authors.lastname: Powles
authors.forename: L
authors.initials: L
authors.lastname: Fry
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000942:Antigens, Bacterial / Q000096:biosynthesis* / Q000097:blood; D015703:Antigens, CD / Q000097:blood; D016022:Case-Control Studies; D002455:Cell Division / Q000276:immunology; D002478:Cells, Cultured; D006801:Humans; D008875:Middle Aged; D011565:Psoriasis / Q000276:immunology*; D011948:Receptors, Antigen, T-Cell / Q000097:blood; D012867:Skin / Q000276:immunology*; D013297:Streptococcus pyogenes / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000942:Antigens, Bacterial; D015703:Antigens, CD; D011948:Receptors, Antigen, T-Cell